For cellular systems like LTE multihop relay nodes are considered for range extension and capacity enhancement, e.g. by signal to noise Ratio (SNR) improvement. According to some proposals relaying networks seem to be an option for broadband wireless data networks like LTE, e.g. for LTE R9 or LTE-A.
For frequency division duplex (FDD) systems an additional time division multiplexing (TDM) structure, for example on subframe basis, may be a suitable relying protocol on layer 2, as it allows for orthogonal transmissions on nodeB—relaying node (NB-RN) and RN—user equipment (RN-UE) links. In the resulting duplex scheme the RN is either connected to the NB or to its attached UEs. In the first case the RN provides UE functionality to the NB and in the second case NB functionality to the UEs.
The basic scheme of such a band structure of a relaying network is schematically depicted in FIG. 1. In the downlink band 101 a relay node (RN) transmits signals to a user equipment (UE) in a first subframe 102 and a nodeB (NB) will transmit signals to the UE or the RN in a second subframe 103. In the uplink band 104 the RN receives signals from the UE in one subframe 105 and the NB will receive signals from the UE or the RN in the next subframe 106. Between the downlink band 101 and the uplink band 104 a duplex gap 107 is present which separates the both in frequencies, which separation in frequencies is schematically depicted by coordinate system 108.
However, there may be a need for a network element and a method of operating a network element which allows an improved performance, in particular which may enable a relaying solution while using LTE R8 conform user equipments.